SVO and carbon trumpets on injectors

[isuzurover Junior Member Find all posts View Profile Close isuzurover]

Some information that may be of interest.

A couple of years ago there was a letter to the editor of the IEAUST newsletter. The letter was from an engineer that had been involved in military research, trialling the operation of diesel engines on SVO (specifically coconut/palm oil).

It was stated that direct injection diesels developed carbon trumpets on the injector nozzles, whereas indirect injection diesels did not. The presence of these carbon deposits was confirmed by a friend of mine who was running an ISUZU (direct injection) diesel on WVO, however he stated that the deposits could be controlled through regular use of injector cleaner.

Has anyone else noticed this???

[isuzurover Junior Member Find all posts View Profile Close isuzurover]

Re: SVO and carbon trumpets on injectors

Another point I should add, is that when my friend first converted his engine to WVO, the compression was down on one cylinder and it would only idle on 3 cylinders (he thought it was an injector pump problem at the time). However when it ran on WVO it would idle on all 4!!!

[Robert Administrator Find all posts View Profile Close Robert]

Re: SVO and carbon trumpets on injectors

Hi Ben, I'd just like to clarify one point:

"converted his engine to biodiesel"

But running on biodiesel needs no conversion. Running SVO or WCO needs conversion, but biodiesel converts the fuel to run on any diesel engine, rather than converting the engine to run on the fuel.

Do you mean that when he ran it on mineral diesel or biodiesel it had problems, but after the conversion it did not?

[isuzurover Junior Member Find all posts View Profile Close isuzurover]

Re: SVO and carbon trumpets on injectors

Hi Ben, I'd just like to clarify one point:

"converted his engine to biodiesel"

But running on biodiesel needs no conversion. Running SVO or WCO needs conversion, but biodiesel converts the fuel to run on any diesel engine, rather than converting the engine to run on the fuel.

Do you mean that when he ran it on mineral diesel or biodiesel it had problems, but after the conversion it did not?

Sorry Robert, meant to type WVO. Have fixed up the post.

When running on mineral diesel the engine idled on 3 of the 4 cylinders (but above idle ran fine). When running on WVO it would idle on all 4 cylinders - and reportedly ran better all round.

[Neutral Biofuels Forum Newbie Find all posts View Profile Close Neutral]

Re: SVO and carbon trumpets on injectors

I have certainly seen carbon building up on the injector tip within a few hours with a low blend of veg oil in diesel. The build up caused a loss of power and efficiency. Full performance was restored by wiping off the carbon. This was in a direct injection stationary engine. The fuel was not heated - it might have been different with heated fuel. No such problem occurred using biodiesel.

By the way I think it would be a good move to avoid the terms WCO and WVO for used cooking oil. This material isn't "waste" and never has been. It was always the raw material for the Yellow Grease trade. It is of course "used" hence the term UCO seems more appropriate.

[Axel Junior Member Find all posts View Profile Close Axel]

Re: SVO and carbon trumpets on injectors

For my 5c worth,
For my engineering thesis I showed that a diesel engine unmodified, by only heating the oil would run SVO, That aside in the Research I found prior to the practice, I came across I full onserious paper by I think SAE Engineers or similar, serious engineer/techincal guys, (which bewildered me) who savagely poopooed the idea of SVO, describing exactly the issues you point out "carbon building up on the injector tip within a few hours "
From the article, I could only take it that they were expecting to run unheated oil, the poor results they got destroyed an otherwise perfect opportunity to a real test. Made me wonder if they decided on the outcome first, based on who was funding the research....
The whole paper was so flawed by a single line mndset, just heat the stuff up....

Had my spill now, ta...
Axe

[liquidgold Junior Member Find all posts View Profile Close liquidgold]

Re: SVO and carbon trumpets on injectors

Hi Axel,
Like the way your approaching it though could you clarify it a bit more because running unheated veg oil in some diesel's would have alot of problems yet they only focused on one? and still heating the oil would have many problems but running on a dual tank svo kit can solve some of the major problems, single tank conversions are avalible these must offer a huge advantge on reducing problems thus the single tank only yet heating is still required. Also current diesel requires additives aswell in cold weather so nothing is perfect.

It boils down to the cheapest engine on the most unmodified fuel under all conditions this is most probably what challegend their resovle.